This project was originally planned as a consortium grant project to correlate several parameters of corrosion kinetics for dental amalgam made from six representative spherical, lathe-cut and dispersion type alloys with the clinical behavior of these amalgams. Since the corrosion aspects of the project were deleted (by Study Section) prior to funding, the research plan has been changed to place the main emphasis upon comparison of various methods for clinical evaluation, including the use of USPHS criteria developed by Ryge, et al., Mahler's method for categorizing marginal fracture according to a standard set of photographs, and Eick's method for stereo-photogrammetric evaluation and quantitation. An attempt will be made to correlate the findings with available information on the corrosion characteristics of the six alloys used. Parallel clinical studies will be conducted at the University of the Pacific and Oral Roberts University Schools of Dentistry.